1. Field of the Invention
This invention relates to a photosensitive adhesive composition, adhesive film obtained using the same, adhesive sheet, semiconductor wafer with adhesive layer, and semiconductor device and electronic components.
2. Related Background of the Invention
In recent years, due to the higher performance and higher functionality of electronic components, various types of semiconductor package have been proposed. In semiconductor packages, adhesives for bonding a semiconductor device to a supporting substrate for mounting the semiconductor device, and adhesives for bonding a semiconductor chip to various types of adherends, are required to have low stress, sticking property at low temperatures, wetproof reliability, and solder-proof reflow properties. In methods which simplify functions, forms and assembly processes for semiconductor packages or electronic parts, it may also be required to have a photosensitive function which allows formation of a pattern. Photosensitivity is a property whereby a part irradiated by light undergoes a chemical change, and becomes soluble or insoluble in an aqueous solution or an organic solvent. If an adhesive having such photosensitivity is used, by exposing it via a photomask and forming a pattern with a developer solution, it is possible to obtain a very fine adhesive pattern. Until now, photosensitive adhesives were based on a polyimide resin precursor (polyamide acid) or polyimide resin (JP-A No. 2000-290501, JP-A No. 2001-329233, JP-A No. 11-24257). However, in the former case, during a ring closure reaction to produce the imide, and in the latter case during the adhesion step, a high temperature of 300° C. or more was required, so thermal damage to surrounding material was severe. There was also the problem that residual heat stress was easily generated.
It has also been attempted to improve sticking property at low temperatures and solder heat resistance by blending and crosslinking a thermosetting resin with an adhesive using a polyimide resin or the like.